A nano drug delivery system loading drugs and chlorin e6 separately to achieve photodynamic-chemo combination therapy

To develop a new drug delivery system (DDS) that can load chemotherapy agents and photosensitizer chlorin e6 (Ce6) onto the pores and surfaces of mesoporous silica nanoparticle (MSN) separately. Doxorubicin (DOX) was loaded into the pores of MSNs. Then, polyethyleneimine (PEI) was used to coat the surface of MSN to protect DOX, and then manganese dioxide (MnO2) nanoparticles were loaded through adding potassium permanganate (KMnO4) to bind with Ce6. Finally, polydopamine (PDA) was coated and coupled with hyaluronic acid (HA). The synthesized versatile nanoparticle was pH-sensitive and exhibited positive photodynamic therapy (PDT) performance. Besides, it could be observed that the nanoparticles were efficiently taken up by tumor cells through confocal laser scanning microscopy (CLSM) and flow cytometry. Additionally, in vitro experiments suggested that the nanoparticles had pleasing toxicity to various tumor cells and equally positive therapeutic effect when curcumin replaced DOX. Our work suggests that the nanoparticles designed by our strategy have satisfactory combination therapy performance and can enable more chemotherapy drugs to be used in photodynamic-chemo combination therapy.